https://bugs.freedesktop.org/show_bug.cgi?id=98005
--- Comment #11 from Andy Furniss adf.lists@gmail.com --- It turns out with more time + different tests that these patches don't fix the original issue.
I can still get too low bitrates depending on timing/luck eg. forcing powerplay/cpufreq to high with the right test stream can get different results from auto. This is testing with the same GOP and (so far) disabling dual instance does seem to always produce the correct bitrate.
I also found another bug = ntsc framerates are not handled. I live in PAL land, so didn't notice this sooner, though we still get /1001 framerates on blu-ray which is how I belatedly noticed.
I made a hacky fix - maybe working out where (if anywhere) the players pass framerate den would be better, but I'll attach it anyway just to see what you think (it only applies to vanilla mesa). Seems to work OK with avconv and gstreamer.